Abstract
We have established that increase in magnesium concentration in LiNbO3:Mg(0.19-5.91 mol% MgO) crystals leads to re-structuring in defective structure and optical anomalies connected with the re-structuring. The anomalies have threshold character. Optical uniformity of crystals was shown to increase at Mg concentration close to a threshold one ~3.0 mol% MgO. IR-absorption spectrum in the area of stretching vibrations of OH groups shifts to a high-frequency area (~50 cm-1 in comparison with other crystals), when Mg concentration nears the second threshold. At this sharp decrease in protons amount and jump-like shift of an absorption edge in the shortwave region are also observed. The shift was shown to be caused by the fact that at 5.5 mol% MgO all point defects NbLi are substitutes by Mg cations and with an increase in Mg concentration, Mg cations occupy Li and Nb sites forming point defects MgLi and MgNb.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
